Most of us are prone to post-traumatic stress after experiencing a traumatic event. But when this stress uncontrollably persists for month or years, we’ve developed the mental health condition known as post-traumatic stress disorder (PTSD).
PTSD has serious implications in how the brain maneuvers. While traumas will vary in circumstance – from combat to sexual assault – the brain changes in a similar manner.
Most notably, your alarm system becomes extremely sensitive and prone to triggers. Our alarm system is a natural necessity as it dictates survival. For example, if you were taking a stroll through the woods and saw a bear, your alarm system would kick in and guide you.
However, people with PTSD will find their alarm systems kicking in at seemingly random moments. More often than not, this alarm system recalls a traumatic event where survival was on the line and associates it with the present. ¹
Throughout this article, we’re going to take a deeper look into how PTSD changes your brain structure. At the end, we invite you to ask further questions.
PTSD and the Brain: A Match Made in Hell
If you struggle with PTSD, then you already know you’re prone to vivid flashbacks of traumatic events that feel very real and threatening. To take things further, you’re also aware that such flashbacks usually occur when you experience a certain cue. ²
This cue is different for everyone, but always relates back to the traumatic event. In one example, if a person experiences PTSD after a car accident where a red car hit them, red cars may trigger a traumatic response.
In turn, many people with PTSD will avoid anything that can be a trigger – whether it’s people objects, or situations. In many regards, it’s this avoidance behavior that makes PTSD such an unbearable condition to live with. And it prevents people from living out their lives.
The problem with avoiding situations is you’re only fueling anxiety. Every time you choose not to participate in a situation, you’re telling your brain that situation is bad. Going of the example of the red cars, you may avoid going outside so as not to see red cars. This informs your brain that red cars are a danger and such self-isolation is protective.
What you need to do is reverse these effects – to be able to go outside and come face-to-face with your triggers.
Of course, this is easier said than done. However, we’re about to lay out the very way in which PTSD has taken control over your brain chemistry. We hope you use this information as a means of overcoming your traumatic event and, in turn, your PTSD.

The Hippocampus and Trauma
The hippocampus is a section in our brains that plays a vital role in our limbic system. Most notably, it’s responsible for developing new memories and, through these, growing our knowledge and emotions. ³
Studies have found that people who struggle with PTSD have a significant decrease in the capacity of their hippocampus. In turn, this causes individuals to have a blurred perception of what is past and what is present. ⁴
Due to a reduced volume in hippocampus activity, a person’s brain is much more vulnerable to triggers. This is why a rape victim may constantly avoid public parks. If s/he was raped in such a setting, their brain has difficulty associating the past from the present and, in turn, places him/her back into the presence of the traumatic event.

The Ventromedial Prefrontal Cortex and Trauma
A part of the prefrontal cortex, the ventromedial prefrontal cortex (vmPFC) is responsible for processing risks and fears. More importantly, the vmPFC is regulates emotional responses that are caused by the amygdala. ⁵
In PTSD patients, it’s been observed that there’s a decreased volume of the vmPFC. In other words, there’s a decreased ability for emotions to properly regulate. In turn, those who struggle with PTSD are vulnerable to anxiety, fear, and stress – even when faced with a situation where this stimuli shouldn’t occur.
It’s important to note that the reason the vmPFC has this response is because of the hippocampus’s difficulty in processing memory. Since new memories that can reassure the vmPFC cannot be formed, the vmPFC takes has difficulty in processing emotional responses. ⁶

The Amygdala and Trauma
The amygdala is another part of the brain that plays a vital role in processing emotions. More particularly, it’s responsible for regulating fear. People with PTSD tend to have a hyperactive amygdala.
This is most notably true when someone with PTSD is presented with a trigger to their traumatic event. However, interestingly, even when not faced with associations of the traumatic even, a person with PTSD still exhibits increased stimuli in their amygdala. ⁷
If you struggle with PTSD and you find yourself “on edge” a lot of the time, it’s most likely due to the increase of amygdala activity. This is common in people who are vulnerable to panic attacks and other forms of anxiety.

Final Word
It’s vital to understand that the hippocampus, the ventromedial prefrontal cortex, and the amygdala all work together as a means of regulating stress and fear. When one of these areas of the brain sees an increase an activity, it’s very likely the others will as well.
Due to this connection, it’s in your best interest to seek out advice from a medical professional as to how to calm brain activity. For PTSD patients, this sometimes involves coming face-to-face with their traumatic event. While the task is daunting, it allows your brain to understand the event has passed and is no longer a threat.
And with this understanding, life in itself will become much less stressful.
Your Questions
Still have questions about how PTSD changes the brain?
We invite you to ask them in the comments section below. If you have any further insight to offer – whether personal or professional – we’d also love to hear from you.
Reference Sources
¹ Dialogues in Clinical Neuroscience: Traumatic stress: effects on the brain
² National Institute of Mental Health: Post-Traumatic Stress Disorder
³ frontiers in Human Neuroscience: The role of the hippocampus in flexible cognition and social behavior
⁴ Dialogues in Clinical Neuroscience: Post-traumatic stress disorder: the neurobiological impact of psychological trauma
⁵ Indian Journal of Psychiatry (Wolters Kluwer – Medknow Publications): Neuropsychology of prefrontal cortex
⁶ MDPI: brain sciences: The Interplay of Hippocampus and Ventromedial Prefrontal Cortex in Memory-Based Decision Making
⁷ Archives of general psychiatry (HHS Public Access): Amygdala volume changes with posttraumatic stress disorder in a large case-controlled veteran group